PUBLIC FUNDING OF STEM CELL RESEARCH ENHANCES LIKELIHOOD OF ATTAINING MEDICAL BREAKTHROUGHS

WASHINGTON -- Public funding of research on human stem cells derived from both adults and embryos provides the most efficient and responsible means to fulfill the promise of stem cells for achieving medical breakthroughs, says a new report from the National Academies' National Research Council and Institute of Medicine. The report clarifies what is known about the scientific potential of stem cells and how it can best be realized.

Existing stem cell lines must be monitored closely for genetic mutations and other limitations, and new stem cell lines will be needed in the future, said the committee that wrote the report. Preventing the human body from rejecting transplanted stem cells also is critical, and research in this area should be pursued aggressively, including research on a technique known as somatic cell nuclear transfer.

"Given the promise of stem cell research for treating and perhaps curing a variety of debilitating diseases, our committee felt strongly that research not be limited, but include work on both human adult and embryonic stem cells," said committee chair Bert Vogelstein, professor of oncology and pathology at the Johns Hopkins University School of Medicine, Baltimore, and a Howard Hughes Medical Institute Investigator. "We also believe that new embryonic stem cell lines will need to be developed in the long run to replace existing lines that become compromised by age, and to address concerns about culture with animal cells and serum that could result in health risks for humans."

To be useful for medical therapies, embryonic stem cells will need to be transformed into different tissues for transplantation into patients, which researchers are only beginning to learn how to do. Whenever tissue transplantation takes place, however, there is always a risk that the body's immune system will reject the new biological material, with life-threatening implications. To ensure that stem cell transplantation therapies can be broadly applied to treat many illnesses and individuals, new means to overcome tissue rejection must be found. A technique called somatic cell nuclear transfer, which can be used to create stem cells that are a genetic match to a patient, may be one way to do this, the report says. This practice, which is ethically controversial and sometimes called "therapeutic cloning," is done by removing the nucleus of an egg cell, inserting genetic material from the transplant recipient, and triggering cell division. Because there is no intention of ever implanting the resulting embryo to produce a child, the nuclear transfer technique should not be confused with reproductive cloning.

Although stem cell research is on the cutting edge of biological science today, it is still in its infancy, and an enormous amount of basic research remains to be done before it can result in medical treatments. Private, for-profit research typically translates the fruits of basic research into medical advances that are widely available to the public, but industry may be reluctant to invest in efforts that could take many years to yield commercial applications. Without government funding of basic research on stem cells, progress toward medical therapies is likely to be hindered. Moreover, public sponsorship of basic research would help ensure that many more scientists could pursue a variety of research questions and that their results are made widely accessible via scientific journals -- two factors that can significantly speed progress. In addition, public funding offers greater opportunities for regulatory oversight and scrutiny of research.

President Bush announced in August that he would allow federal financial support of research that uses embryonic stem cells being cultured in laboratories around the world, but would prohibit funding for the development of new lines that involve the creation and destruction of additional embryos. However, the Academies' report says that new stem cell lines will be needed given two unavoidable factors: Harmful genetic mutations are likely to accumulate in cell lines over time, and most of the existing lines have been cultured with animal cells or serum that could lead to potential human health risks.

Stem cells are unspecialized cells that can renew themselves indefinitely and, under the right conditions, can develop into more mature cells with specialized functions. They are found in embryos at early stages of development, in some fetal tissue, and in some adult organs, although isolating adult stem cells is very difficult and multiplying them outside the body is not yet possible in most cases. In addition, there is only preliminary evidence that cells obtained from an adult organ can be coaxed into becoming tissue types other than those characteristic of the original organ. In contrast, embryonic stem cells can be grown in the laboratory and appear to be capable of becoming, or "differentiating" into, virtually any cell type.

The ability to take tissue derived from these cells and transplant it into the human body to restore lost function may be a long way off, the committee said, but there have been some encouraging studies involving animals. For example, transplanted embryonic stem cells from mice have restored some insulin regulation ability in mice with diabetes, relieved symptoms of Parkinson's disease in rodents, and partially restored neural function in animals with spinal cord injuries. The committee called such studies promising albeit not definitive evidence that similar treatments could be effective in humans.

In light of the ethical dilemmas and scientific uncertainties raised by stem cell research, the committee called for the creation of a national advisory body made up of leading scientists, ethicists, and other stakeholders to be established at the National Institutes of Health (NIH). This group could ensure that proposals for federal funding to work on embryonic stem cells are justified on scientific grounds and meet current and future federally mandated ethical guidelines. The committee noted that in the past NIH has set up similar watchdog panels, such as the Recombinant DNA Advisory Committee, which oversees this once-controversial genetic engineering research.

Aware and respectful of the wide array of social, political, legal, ethical, and economic issues that must be considered, the committee held a workshop attended by stem cell scientists from academia and industry, policy-makers, ethicists, and religious leaders, and based its findings in part on their presentations. The study was sponsored by the National Academies with additional funding from the Ellison Foundation. The National Research Council and Institute of Medicine are private, nonprofit organizations that provide science, technology, and health policy advice under a congressional charter granted to the National Academy of Sciences. The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering. A committee roster follows.

NOTE: The report Stem Cells and the Future of Regenerative Medicine is available on the Internet at http://www.nap.edu. Copies are available for purchase from the National Academy Press; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

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NATIONAL RESEARCH COUNCILDivision on Earth and Life StudiesBoard on Life Sciences

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INSTITUTE OF MEDICINEBoard on Neuroscience and Behavioral Health

Committee on the Biological and Biomedical Applications of Stem Cell Research